Surgical scalpel blades are usually packaged individually in an aluminum foil wrap and are irradiated for sterilization purposes. The sterile foil wrap is torn open in the operating room ("O.R.") in a hospital or clinic, and the blade is removed and mounted on a surgical scalpel. The scalpel has a forwardly-projecting portion (referred to in the art as a "cleat") and this cleat is inserted within a longitudinal closed slot formed in the blade, thereby mounting the blade on the scalpel. The blade is relatively thin and flexible, the cleat on the scalpel has a groove to receive the blade, and the mounting is with a slight "snap" fit or "click".
Some scalpel blades, which are used in microsurgery, are super sharp and are packaged in a molded plastic package consisting of a base and a pivoted cover.
The scalpel blades are usually changed several times during a medical procedure in the O.R., since it is imperative that the sharpness of the blades be maintained. The blades are usually changed by a nurse or O.R. technician (called the "tech").
Whether the blade is packaged in an aluminum foil or in a molded plastic package, the blade is removed therefrom; and during the blade mounting process, the tech holds the scalpel in one hand and the blade in the other hand and slips the blade on to the cleat on the scalpel. These blades are roughly an inch to an inch-and-a-half long and (of course) are razor sharp, so it is not at all uncommon for the tech to be nicked or cut while mounting one of the blades, thereby causing blood flow.
If the patient is H.I.V.-infected, the tech may sero-convert and become H.I.V.-infected leading to the deadly AIDS disease. Conversely, if the tech is an H.I.V. carrier, the patient or the other health care providers in the O.R. are at risk. The same is true with respect to hepatitis or other infectious diseases.
The nurse or tech is very often under intense pressure in the O.R. and may become temporarily distracted while in the process of changing blades. This tends to aggravate the existing problem.